Organofluorine compounds and fluorinating agents Part 28. New perfluoroalkyl substituted chiral mesogens

Article abstract of DOI:10.1016/S0022-1139(02)00310-X

The perfluorohexyl-aryl-thioethers 3 and 4, building blocks for the synthesis of the chiral target mesogens 12-15, were prepared by dithionite-mediated S-perfluoroalkylation of the p-substituted thiophenols 1 and 2. The phenolic HO-group of 3 was O-glucos

Full text of DOI:10.1016/S0022-1139(02)00310-X

Journal of Fluorine Chemistry 120 (2003) 85±91
Organo¯uorine compounds and ¯uorinating agents
Part 28. New per¯uoroalkyl substituted chiral mesogens$
*
È
Dirk Schwabisch, Ralf Miethchen
Universitat Rostock, Fachbereich Chemie, Albert-Einstein-Strasse 3a, D-18051 Rostock, Germany
È
Received 21 September 2002; received in revised form 7 November 2002; accepted 12 November 2002
Abstract
The per¯uorohexyl-aryl-thioethers 3 and 4, building blocks for the synthesis of the chiral target mesogens 12±15, were prepared by
dithionite-mediated S-per¯uoroalkylation of the p-substituted thiophenols 1 and 2. The phenolic HO± group of 3 was O-glucosylated with
pentaacetyl-D-glucopyranose to 5 followed by deacetylation forming the tetrol 6 and by acetalizing with 4-(4-per¯uorohexylsulfanyl-
benzoyloxy)-benzaldehyde-dimethylacetal (8) generating the dihydroxy-intermediate 9. The latter contains two per¯uorohexylthio chains.
Alternatively, the dimethylacetal 8 was linked to p-octylphenyl-b-D-glucopyranoside (10) giving the mixed octyl/per¯uorohexyl substituted
p-octylphenyl-4,6-O-[40-(400-per¯uorohexylsulfanyl)-benzoyloxy]-benzylidene-b-D-glucopyranoside (11). Compound 8 was obtained via
esteri®cation of 4 with p-hydroxy-benzaldehyde to 4-(4-per¯uorohexylsulfanyl-benzoyloxy)-benzaldehyde (7). Finally, the diols 9 and 11
were dehydroxylated to 12 and 13 followed by hydrogenation yielding 14 and 15, respectively. Tetrol 6, diols 9, 11 and the non-amphiphilic
compounds 7, 12±15 are thermotropic liquid crystals.
# 2002 Elsevier Science B.V. All rights reserved.
Keywords: Fluorinated compounds; Per¯uoroalkylation; Carbohydrates; Liquid crystals
1. Introduction
structures with per¯uoroalkyl chains in place of alkyl chains,
because the lower nucleophilicity of ¯uorinated building
blocks (e.g. per¯uorohexylpropyl-phenylether) prevents the
®rst synthesis step. However, per¯uoroalkylated non-amphi-
philic liquid crystals based on carbohydrates are easily
accessible via radical per¯uoroalkylation of unsaturated
precursors [10]. Radical initiated per¯uoroalkylations of
unsaturated compounds and of thiols are well-established
methods to introduce per¯uoroalkyl chains in organic sub-
strates (see [11±14] and papers cited therein).
In the last two decades interest in carbohydrate-derived
liquid crystals increased greatly (for reviews see [2±6]). The
introduction of per¯uoroalkyl chains has a remarkable effect
on the stabilization of mesophases, especially on those
formed by amphiphilic mesogens [7]. This is due to the
higher stiffness combined with loss of conformational free-
dom of per¯uoroalkyl chains compared with alkyl chains.
Furthermore, the intramolecular contrast between the polar
head group and the hydrophobic chain is higher in amphi-
philes when an alkyl chain is replaced by a per¯uoroalkyl
chain of same length. This usually leads to higher clearing
points of the corresponding per¯uoroalkylated thermotropic
amphiphiles. Recently, a review was published discussing
these effects in detail [8].
2. Results and discussion
2.1. Synthesis
Aromatic building blocks are often used in liquid crystals.
Recently, ®rst examples of liquid crystals were described in
which ¯uoroalkyl aromatics are linked to carbohydrates
[15]. Our strategy to prepare further new per¯uoroalkyl
substituted mesogens uses as the key step a radical S-
per¯uoroalkylation mediated by sodium dithionite. The
thiophenols 1 and 2 formed with 1-iodo-per¯uorohexane
the thioethers 3 and 4 in yields of 43 and 78%, respectively.
4-Per¯uoroalkylsulfanyl-phenol 3 was subsequently gluco-
In 1996, Vill et al. [9] described an ef®cient pathway to
synthesize chiral non-amphiphilic carbohydrate-derived
liquid crystals starting with a Ferrier reaction. The reported
synthesis strategy is not practicable to build up similar
$ For Part 27, see [1].
* Corresponding author. Tel.: ‡49-381-498-6420;
fax: ‡49-381-498-6412.
E-mail address: ralf.miethchen@chemie.uni-rostock.de (R. Miethchen).
0022-1139/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 1 1 3 9 ( 0 2 ) 0 0 3 1 0 - X

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D. Schwabisch, R. Miethchen / Journal of Fluorine Chemistry 120 (2003) 85±91
86
presence of trimethyl orthoformate giving dimethyl acetal
8 (Scheme 1).
Compound 6 was connected with dimethylacetal 8 by a
transacetalizing reaction catalyzed by methanesulfonic acid.
The resulting dihydroxy derivative 9 contains two per¯uoro-
alkyl chains. In the same manner the non-¯uorinated
amphiphile 10 [18] was connected with dimethylacetal 8
yielding the mixed alkyl/per¯uoroalkyl substituted deriva-
tive 11 (Scheme 2).
To obtain the non-amphiphilic target products 12 and 13,
the dihydroxy derivatives 9 and 11 were dehydroxylated by
application of a modi®ed method of Garegg and Samuelsson
[19] (Scheme 3). Thus, the diols 9 and 11 were treated for 3 h
with PPh3, triiodoimidazole and imidazole in dry xylene at
130 8C. The isolation of the pure products 12 and 13
required a separation by ¯ash chromatography.
The structures of the compounds 9, 11±13 are
supported by 1H, 13C, and 19F NMRspectra including
correlation spectra. It is noteworthy that compound 9 is
insoluble in all relevant solvents at room temperature.
Therefore, the NMRspectra of this compound were
recorded at 40 8C, however, the optical rotation was not
measured.
The unsaturated compounds 12 and 13 were ®nally
treated with dihydrogen and palladium on charcoal to
hydrogenate the CˆC double bond (Scheme 3). These
hydrogenations gave a surprise. Whereas the mixed alkyl/
per¯uoroalkyl derivative 13 yielded the expected saturated
product 14, compound 12 reacted in a different way. In this
case, a reductive cleavage of the glycosidic bond occurs
accompanied by migration of the double bond yielding 3-
deoxyglucal 15. The structure of the latter is supported by
NMRspectroscopic data. Thus, the C-1 signal of 15 shows a
signi®cant down®eld shift compared to starting material 12
(12: d ˆ 96:3 ppm; 15: d ˆ 143:1 ppm). Furthermore, a
second CH2 group is found at 26.3 ppm (DEPT spectrum)
and the 19F NMRspectrum of 15 shows only the character-
istic signals of one SC6F13 group. The SCF2-¯uoro signal is
easily assigned. Whereas compound 12 shows two multi-
plets of SCF2 groupings at d ˆ À85:8 and À87.1 ppm, the
Scheme 1.
sylated with glucose pentaacetate in a boron tri¯uoride
catalyzed reaction analogously to [16] and the resulting b-
glucoside 5 was deprotected analogously to [17] yielding the
amphiphile 6 (Scheme 1). Furthermore, per¯uoroalkylsulfa-
nyl-benzoic acid 4 was treated with p-hydroxy-benzaldehyde
and 4-(dimethylamino)-pyridine in dichloromethane yielding
aldehyde 7 followed by acetalizing with methanol in the
Scheme 2.

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D. Schwabisch, R. Miethchen / Journal of Fluorine Chemistry 120 (2003) 85±91
87
measurements (transition temperatures given in Table 1 are
DSC data). The textures observed under the polarizing
microscope allowed an assignment of the phase type. All
mesogens except compound 6 show a very colorful fan-like
texture, which is typical for smectic A phases. The texture of
compound 6 is less colored, however, likewise, a smectic A
phase type. The non-amphiphilic mesogen 12 showed under
certain circumstances polymorphism. When the isotropic
melt of 12 was cooled down, a fan-shaped texture (smectic A
phase) as well as a striated fan-shaped texture (chiral smectic
CÃ phase) were observed.
However, the appearance of the striated fan-shaped texture
varies depending on the cooling rate, i.e. the slower the
sample is cooled down, the higher is this transition point.
DSC measurements indicate that compound 12 gradually
decomposes in the corresponding temperature range
(Table 1), i.e. the smectic CÃ phase is probably induced by
any reaction products. A further phenomenon was observed
in the case of liquid crystals 11 and 13. Whereas on heating of
11 and 13 the transition temperatures of polarizing micro-
scopic investigation and DSC measurements are easily
detectable, the behavior on cooling down is quite different.
The liquid crystalline textures can certainly be observed
under the polarizing microscope, but the DSC measurements
show no energetic effects on cooling of their melts (Table 1).
A further result is noteworthy. Compared to the other
mesogens, the enthalpy value for the transition smectic A/
isotropic liquid of compound 14 is signi®cantly higher than
the transition crystalline/smectic A (Table 1).
Scheme 3.
19F NMRspectrum of compound 15 shows only the signal at
d ˆ À85:8 ppm.
2.2. Thermal behavior
3. Experimental
The thermotropic liquid crystalline properties of the tetrol
6, the diols 9, 11 and the non-amphiphilic mesogens 7, 12±
15 were investigated by polarizing microscopy and by DSC
The reactions were followed by thin layer chromatogra-
phy using pre-coated aluminum sheets (silica gel 60, F 254,
Table 1
Thermal data of the mesogens 6, 7, 9, and 11±15 based on DSC measurements
No.
6
Transition temperatures
ꢀC
Enthalpies (J/g)
Comments
226 ꢀ
C
cr16!8 SA ! i
DHcr!S ˆ 45:93
Decomposition while melting
A
74 ꢀ
C
114 ꢀ
C
7
cr „ SA11„0 ꢀ i
DHcr!S ˆ 45:06, DHS
ˆ 4:84
ˆ 2:42
ˆ 6:37
A!i
A!i
A!i
A
54 ꢀC
179 ꢀ
C
C
213 ꢀ
C
9
cr „ SA20„0 ꢀ i
DHcr!S ˆ 30:57, DHS
A
138 ꢀ
C
C
C
ꢀC
229 ꢀ
11
cr15!0 SA ! i
DHcr!S ˆ 32:46, DHS
Reentrance of lc-phase only under
microscope, no recrystallization
A
12
DHcr!S ˆ 45:22, DHS
ˆ 7:25
Annotations (see text)
A!i
A!i
A
147 ꢀ
C
211 ꢀ
C
13
14
15
cr „ SA20„4 ꢀCi
DHcr!S ˆ 39:30, DHS
ˆ 15:26
No DSC-values for cooling
No recrystallization
A
112 ꢀC
195 ꢀ
C
42 ꢀ
C
170 ꢀ
C
cr1 ! cr2 ! SA18„5 ꢀ i
DHcr !cr ˆ 12:91,
1
2
C
DHcr !S ˆ 4:84, DHSA!i ˆ 64:23
136 ꢀ
C
160 ꢀ
C
2
A
cr „ SA15„7 ꢀCi
DHcr!S ˆ 61:02, DHS
ˆ 6:05
A!i
A
110 ꢀ
C

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D. Schwabisch, R. Miethchen / Journal of Fluorine Chemistry 120 (2003) 85±91
88
Merck); detection was affected by observation under UV
irradiation (254 nm) or spraying with 10% methanolic sul-
furic acid solution and subsequent thermal treatment. Silica
gel 60 (0.062±0.2 mm, Merck) and silica gel 60 (40±63 mm,
Merck), respectively, were used for column chromato-
graphic separations. All solvents were puri®ed and dried
using standard procedures [20]. Melting points were deter-
mined with a Leitz Laborlux 12 Pol microscope equipped
with a Mettler FP 90 hot stage. Optical rotations were
measured on a polarimeter Polar LmP (IBZ Meûtechnik)
and the NMRspectra were recorded on a Bruker AC-250 and
a Bruker ARX-300 using TMS and CCl3F as internal stan-
dards, respectively. Chemicals: 1,2,3,4,6-penta-O-acetyl-b-
D-glucopyranose (Fluka), 1-iodo-per¯uorohexane (Fluka),
sodium dithionite (Fluka), 4-mercaptophenol (Aldrich), 4-
mercaptobenzoic acid (Fluka), 4-(dimethylamino)-pyridine
(Fluka), triphenylphosphine (Fluka), dicyclohexyl carbodii-
mide (Fluka), trimethylorthoformate (Fluka), Amberlite IR-
120 (Fluka), Amberlite IRA-400 (Fluka).
extracted three times with diethyl ether (50 ml each). The
combined organic phases were washed with water (20 ml),
dried (Na2SO4) and concentrated under reduced pressure. The
residue was recrystallized from aq. MeOH yielding 2.96 g
(78%) of 4. Colorless crystals; mp 184 8C.
1H NMR(300 MHz, Me SO-d6): d (ppm) ˆ 13.35 (br,
2
1H, COOH), 8.04 (m, 2H, Ph), 7.02 (m, 2H, Ph); 13C NMR
(63 MHz, Me2SO-d6): d (ppm) ˆ 164.2 (s, COOH), 134.9
(s), 131.5 (s), 128.2 (s), 124.2 (m); 19F NMR(235 MHz,
Me2SO-d6): d (ppm) ˆ À80.5 (s, CF3), À86.5 (m, SCF2),
À119.4, À121.7, À123.1, À126.4 (4s, 4CF2).
C13H5F13O2S (472.22): Calcd. C: 33.07%, H: 1.07%, S:
6.79%; found C: 32.92%, H: 1.07%, S: 7.02%.
3.3. (4-Perfluorohexylsulfanyl-phenyl)-2,3,4,6-tetra-O-
acetyl-b-D-glucopyranoside (5)
To a solution of compound 3 (3.5 g, 7.88 mmol) and
1,2,3,4,6-penta-O-acetyl-b-D-glucopyranose (6.0 g, 15.37
mmol) in dry dichloromethane (18 ml) an ethereal solution
of boron tri¯uoride (1.0 ml) was added at 0 8C under inert
gas atmosphere. This mixture was allowed to warm up to
room temperature and then was stirred for 24 h. After
completion of the reaction (tlc-control), the solution was
poured onto saturated aq. NaHCO3 solution (50 ml) with
stirring. The organic phase was separated and the aqueous
phase was extracted with dichloromethane (50 ml). The
combined organic extracts were washed with water, dried
over sodium sulfate and concentrated under reduced pres-
sure. The residue was puri®ed by column chromatography
(eluent heptane/EtOAc 5:1 (v/v), 5: RF ˆ 0:05) and recrys-
tallized from aqueous ethanol yielding 4.02 g (66%) of 5.
3.1. 4-(Perfluorohexylsulfanyl)-phenol (3)
To a stirred and cooled solution of 4-mercaptophenol (1)
(5.0 g, 40 mmol) in DMF (100 ml) saturated aq. NaHCO3-
solution (100 ml) and 1-iodo-per¯uorohexane (17.3 ml,
77.6 mmol) were added. Then sodium dithionite (6.97 g,
40 mmol) was added in small portions under a inert gas
atmosphere. After completion of the reaction (tlc-control
heptane/EtOAc 5:1 (v/v), 3: RF ˆ 0:26) the reaction mixture
was diluted with diethyl ether (200 ml), washed with brine
(100 ml) and water (100 ml), dried (Na2SO4) and concen-
trated under reduced pressure.
The residue was puri®ed by column chromatography
(heptane/EtOAc 5:1 (v/v), RF ˆ 0:26) followed by sublima-
tion at 150 8C bath temperature and pressure <1 mmHg
yielding 7.69 g (43%) of 3; mp 28±30 8C.
White crystals; mp 111±112 8C; ‰aŠ23: À15.18 (CHCl3,
D
c ˆ 0:98).
1H NMR(250 MHz, CDCl 3): d (ppm) ˆ 7.58 (m, 2H, Ph),
7.01 (m, 2H, Ph), 5.29 (m, 2H, H-1, H-2), 5.16 (m, 2H, H-3,
3
1H NMR(250 MHz, CDCl 3): d (ppm) ˆ 7.52 (m, 2H, Ph),
7.86 (m, 2H, Ph), 5.24 (s, 1H, ±OH); 13C NMR(63 MHz,
CDCl3): d (ppm) ˆ 158.2 (s, Cq), 139.4 (s, Ct), 116.5 (s, Ct);
H-4), 4.28 (dd, 1H, J6a=6b ˆ 12:3 Hz, J5=6a ˆ 5:4 Hz, H-
2
3
6a), 4.16 (dd, 1H, J5=6b ˆ 2:5 Hz, H-6b), 3.89 (ddd, 1H,
3J4=5 ˆ 8:0 Hz, H-5), 2.04 (m, 12H, CH3); 13C NMR
(63 MHz, CDCl3): d (ppm) ˆ 170.5, 170.2, 169.4, 169.2
(4s, CˆO), 158.9 (s, Ph-Cq), 139.1 (s, Ph-Ct), 117.5 (s, Ph-
Ct), 116.3 (m, Ph-Cq), 98.2 (s, C-1), 72.5, 72.2, 71.0, 68.1
(4s, C-2, C-3, C-4, C-5), 61.9 (s, C-6), 20.6 (s, CH3); 19F
19F NMR(235 MHz, CDCl ): d (ppm) ˆ À80.5 (m, CF3),
3
À87.5 (s, SCF2), À119.0, À121.2, À122.5, À125.9 (4s,
‡
4CF2); m=z ˆ 444 [M] ; HRMS 443.98135.
C12H5F13OS (443.99): Calcd. C: 32.45%, H: 1.13%, S:
7.22%; found C: 32.43%, H: 1.40%, S: 7.08%.
NMR(235 MHz, CDCl 3):
d
(ppm)
ˆ À80.5 (t,
3JF=F ˆ 9:5 Hz, CF3), À87.2 (t, JF=F ˆ 13:0 Hz, SCF2),
À119.0 (s, CF2), À121.2 (s, CF2), À122.5 (s, CF2),
À125.9 (s, CF2).
3
3.2. 4-(Perfluorohexylsulfanyl)-benzoic acid (4)
To a stirred mixture of 4-mercaptobenzoic acid (2) (1.23 g,
8.0 mmol) in DMF (80 ml) and saturated aq. NaHCO3-solu-
tion (80 ml) 1-iodo-per¯uorohexane (3.47 ml, 16 mmol) and
sodium dithionite (1.39 g, 8.0 mmol) were added. The stir-
ring was continued at room temperature for approximately
2 h. After complete conversion (tlc-control, eluent EtOAc/
toluene 1:1 (v/v)), the reaction mixture was diluted with
brine (50 ml) and acidi®ed with concentrated hydrochloric
acid to slight acidic reaction (pH 6). This solution was
C26H23F13O10S (774.50): Calcd. C: 40.32%, H: 2.99%, S:
4.14%; found C: 40.53%, H: 3.16%, S: 4.44%.
3.4. p-Perfluorohexylsulfanyl-phenyl-b-D-glucopyranoside
(6)
Compound 5 (4.52 g, 5.8 mmol) was dissolved in dry
MeOH (100 ml) followed by addition of 1% methanolic
sodium methoxide (10 ml). After stirring for 3 h at room

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D. Schwabisch, R. Miethchen / Journal of Fluorine Chemistry 120 (2003) 85±91
89
temperature the reaction was ®nished. Then an acidic ion
exchanger resin (Amberlite IR-120; 5.0 g) was added and
stirring was continued for further 10 min. After ®ltration, the
solution was concentrated under reduced pressure. Then
methanol was added in such an amount that the resulting
crude product dissolved at room temperature. After that
acetonitrile was added (about double the volume of MeOH)
and the resulting clear solution was concentrated at room
temperature at normal pressure until crystals of the pure
product precipitate (3.43 g, 97%). Thermotropic behavior:
formate (0.31 ml, 2.8 mmol) and an acidic ion exchanger
resin (Amberlite IR-120, 0.5 g). This mixture was re¯uxed
for 4 h under exclusion of moisture. After completion of the
reaction (tlc-control) the resin was removed by ®ltration and
the ®ltrate was neutralized by a basic ion exchanger resin
(Amberlite IRA-400, 0.3 g). After 5 min the solution was
concentrated under reduced pressure and crude product was
recrystallized from isopropanol yielding 1.49 g (98.4%) of
8; colorless crystals; mp 60 8C.
1H NMR(250 MHz, CDCl ): d (ppm) ˆ 8.23 (m, 2H,
3
mp 169 8C, SA-phase, cp 226 8C; ‰aŠ25: À37.38 (MeOH,
Ph), 7.82 (m, 2H, Ph), 7.53 (m, 2H, Ph), 7.22 (m, 2H, Ph),
5.43 (s, 1H, acetal-H), 3.34 (s, 6H, CH3); 13C NMR
(63 MHz, CDCl3): d (ppm) ˆ 190.9 (s, Cq), 164.0 (s,
Cq), 150.7 (s, Cq), 137.1 (s, Ct), 130.9 (s, Ct), 128.1 (s,
Ct), 121.3 (s, Ct), 102.5 (s, acetal-C), 52.7 (s, CH3); 19F
D
c ˆ 1:12).
1H NMR(250 MHz, CD OD): d (ppm) ˆ 7.60 (m, 2H,
3
Ph), 7.18 (m, 2H, Ph), 4.97 (m, 1H, H-1), 3.89 (m, 1H), 3.68
(m, 1H), 3.45 (m, 4H); 13C NMR(63 MHz, CD OD): d
3
(ppm) ˆ 164.7 (s, Ph-Cq), 143.1 (s, Ph-Ct), 121.6 (s, Ph-Ct),
118.4 (s, Ph-Cq), 104.6 (s, C-1), 81.2, 80.8, 77.7, 74.1 (4s, C-
2, C-3, C-4, C-5), 65.3 (s, C-6); 19F NMR(235 MHz,
NMR(235 MHz, CDCl 3):
d
(ppm)
ˆ À85.7 (t,
3JF;F ˆ 11:0 Hz, CF3), À91.0 (t, JF;F ˆ 12:0 Hz, SCF2),
À123.9, À126.3, À127.7, À131.0 (4m, 4CF2); IR(KBr,
cmÀ1) 1740.7 (CˆO).
3
3
CD3OD): d (ppm) ˆ À79.8 (t, JF=F ˆ 10:5 Hz, CF3),
3
À86.3 (t, JF=F ˆ 14:0 Hz, SCF2), À117.7 (s, CF2),
C22H15F13O4S (622.40): Calcd. C: 42.46%, H: 2.43%, S:
5.15%; found C: 42.48%, H: 2.40%, S: 5.35%.
À119.8 (s, CF2), À121.2 (s, CF2), À124.7 (s, CF2).
C18H15F13O6S (606.35): Calcd. C: 35.66%, H: 2.49%, S:
5.29%; found C: 36.05%, H: 2.39%, S: 5.46%.
3.7. (4-Perfluorohexylsulfanyl-phenyl)-(R)-4,6-O-[40-(4-
perfluorohexylsulfanyl)-benzoyloxyl]-benzylidene-b-D-
glucopyranoside (9)
3.5. 4-(4-Perfluorohexylsulfanyl-benzoyloxy)-
benzaldehyde (7)
Dimethylacetal 8 (3.5 g, 5.62 mmol) and compound 6
(3.5 g, 5.77 mmol) were dissolved in dry DMF (150 ml).
Subsequently, methanesulfonic acid (1 ml) was added. This
mixture was attached to a rotary evaporator and kept there
for 3 h at 60 8C bath temperature and 45 mbar. After com-
pletion of the reaction (tlc-control), saturated aq. NaHCO3
solution (200 ml) was added and the product was extracted
by ethyl acetate (twice 100 ml). The combined organic
phases were dried (Na2SO4) and concentrated in vacuo.
The residue was puri®ed by ¯ash chromatography using
an eluent gradient (1 l of toluene/EtOAc 10:1 (v/v), 2 l
toluene/EtOAc 1:1 (v/v) (RF ˆ 0:38 at toluene/EtOAc 1:1
(v/v)) yielding 3.47 g, (53.0%) of 9. Colorless crystals; mp
151.5 8C, SA-phase, cp 225 8C.
Compound 4 (1.416 g, 3.0 mmol) was dissolved in dry
dichloromethane (70 ml). Then 4-hydroxy-benzaldehyde
(0.366 g, 3.0 mmol), 4-(dimethylamino)-pyridine (0.36 g,
0.3 mmol) and dicyclohexyl carbodiimide (0.927 g,
4.5 mmol) were added. This reaction mixture was stirred
at room temperature and exclusion of moisture for about
72 h (tlc-control, heptane/EtOAc 5:1 (v/v), RF ˆ 0:36). The
precipitated dicyclohexylurea was removed by ®ltration, the
®ltrate was concentrated under reduced pressure and the
solid residue was recrystallized from isopropanol yielding
1.5 g (60%) of compound 7 as colorless needles. Thermo-
tropic behavior: mp 72 8C, SA-phase, cp 120 8C.
1H NMR(300 MHz, Me 2SO-d6): d (ppm) ˆ 10.04 (s, 1H,
±CHO), 8.26 (m, 2H, Ph), 8.04 (m, 2H, Ph), 7.96 (m, 2H,
1H NMR(300 MHz, CDCl ): d (ppm) ˆ 8.22 (m, 2H,
3
Ph), 7.58 (m, 2H, Ph); 13C NMR(75 MHz, Me SO-d6): d
Ph), 7.79 (m, 2H, Ph), 7.59 (m, 4H, Ph), 7.24 (m, 2H, Ph),
7.09 (m, 2H, Ph), 5.60 (s, 1H, acetal-H), 5.08 (d,
2
(ppm) ˆ 191.8 (s, Cq), 163.1 (s, Cq), 154.9 (s, Cq), 137.2 (s,
Ct), 134.1 (s, Cq), 131.3 (s, Cq), 131.0 (s, Ct), 130.9 (s, Ct),
122.7 (s, Ct), 99.3 (s, Ct); 19F NMR(235 MHz, Me 2SO-d6):
3
3J1=2 ˆ 7:7 Hz, 1H, H-1), 4.40 (dd, J3=4 ˆ 4:4 Hz,
3J4=5 ˆ 10:5 Hz, 1H, H-4), 3.94±3.72 (m, 3H, H-2, H-3,
H-6a), 3.69±3.57 (m, 2H, H-5, H-6b); 13C NMR(75 MHz,
CDCl3): d (ppm) ˆ 163.9 (s, Cq), 159.3 (s, Ph-Cq), 151.6 (s,
Ph-Cq), 139.2 (s, Ph-Ct), 137.0 (s, Ph-Ct), 135.0 (s, Ph-Cq),
132.1 (s, Ph-Cq), 130.9, 127.8, 121.5, 117.8 (4s, Ph-Ct),
101.5, 100.9 (2s, acetal-C, C-1), 80.3, 74.5, 73.5, 66.9 (4s,
C-2, C-3, C-4, C-5), 68.6 (s, C-6); 19F NMR(235 MHz,
CDCl3): d (ppm) ˆ À80.5 (s, CF3), À85.8 (m, SCF2), À87.1
(m, SCF2), À118.8 (m, CF2), À121.2 (s, CF2), À122.5 (s,
CF2), À125.8 (s, CF2).
3
d (ppm) ˆ À80.4 (t, JF;F ˆ 10:0 Hz, CF3), À86.2 (t,
3JF;F ˆ 12:0 Hz, SCF2), À119.1, À121.4, À122.7, À125.9
(4 m, 4CF2); IR(KBr, cm À1) 1746.5 (CˆO); 1698.3 (CˆO).
C20H9F13O3S (576.33): Calcd. C: 41.68%, H: 1.57%, S:
5.56%; found C: 41.74%, H: 1.76%, S: 5.62%.
3.6. 4-(4-Perfluorohexylsufanyl-benzoyloxy)-benzaldehyde-
dimethylacetal (8)
Aldehyde 7 (1.4 g, 2.43 mmol) was dissolved in dry
MeOH (120 ml) followed by addition of trimethylortho-
C38H22F26O8S2 (1164.67): Calcd. C: 39.19%, H: 1.90%,
S: 5.51%; found C: 39.16%, H: 1.91%, S: 5.55%.

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D. Schwabisch, R. Miethchen / Journal of Fluorine Chemistry 120 (2003) 85±91
90
3.8. p-Octylphenyl-(R)-4,6-O-[40-(4-
perfluorohexylsulfanyl)-benzoyloxy]-benzylidene-b-D-
glucopyranoside (11)
(m, 2H, Ph), 6.31 (d, 3J2=3 ˆ 10:2 Hz, 1H, H-2 or H-3), 6.00
(m, 1H, H-1), 5.85 (dd, 1H, H-2 or H-3), 5.66 (s, 1H, acetal-
H), 4.64±4.35 (m, 2H, H-4, H-6a), 3.91 (m, 2H, H-5, H-6b);
13C NMR(75 MHz, CDCl 3): d (ppm) ˆ 164.1 (s, Cq), 159.3
(s, Ph-Cq), 151.4 (s, Ph-Cq), 139.3 (s, Ph-Ct), 137.2 (s, Ph-
Ct), 135.3 (s, Ph-Cq), 132.7 (s, Ph-Cq), 132.0, 126.7 (2s, C-2,
C-3), 131.0 (s, Ph-Ct), 127.8 (s, Ph-Ct), 121.6, 117.5 (2s, Ph-
Ct), 101.6 (s, acetal-C), 96.3 (s, C-1), 74.7, 71.2 (2s, C-4, C-
A mixture of p-octylphenyl-b-D-glucopyranoside [16]
(1.5 g, 8.15 mmol) and compound 8 (2.5 g, 4.01 mmol)
was dissolved in dry DMF (75 ml). Then methanesulfonic
acid (0.75 ml) was added and the mixture was treated as
described for compound 9. An amount of 1.2 g (32%) of
colorless crystals 11 were isolated, mp 150 8C, SA-phase, cp
5), 69.0 (s, C-6); 19F NMR(235 MHz, CDCl ): d (ppm) ˆ
3
À80.5 (s, CF3), À85.8 (m, SCF2), À87.1 (m, SCF2), À118.8
(m, CF2), À121.2 (s, CF2), À122.5 (s, CF2), À125.8 (s, CF2).
C38H20F26O6S2 (1130.65): Calcd. C: 40.37%, H: 1.78%,
S: 5.67%; found C: 40.56%, H: 1.78%, S: 5.73%.
229 8C; ‰aŠ24: À11.88 (CHCl3, c ˆ 1:09).
D
1H NMR(250 MHz, CDCl 3): d (ppm) ˆ 8.22 (m, 2H, Ph),
7.79 (m, 2H, Ph), 7.58 (m, 2H, Ph), 7.22 (m, 2H, Ph), 7.09
(m, 2H, Ph), 6.96 (m, 2H, Ph), 5.58 (s, 1H, acetal-H), 4.98 (d,
3
3J1=2 ˆ 7:6 Hz, 1H, H-1), 4.38 (dd, J3=4 ˆ 4:6 Hz,
3.10. (4-Octylphenyl)-(R)-4,6-O-[40-(4-
3J4=5 ˆ 10:5 Hz, 1H, H-4), 3.94±3.73 (m, 3H, H-2, H-3
H-6a), 3.69±3.52 (m, 2H, H-5, H-6b), 2.99 (br, 1H, OH),
2.82 (br, 1H, OH), 2.55 (t, 2H, Ph-CH2), 1.59±1.26 (m, 12H,
perfluorohexylsulfanyl)-benzoyloxy]-benzylidene-2,3-
dideoxy-b-D-erythro-hex-2-enopyranoside (13)
CH2), 0.87 (t, 3H, CH3); 13C NMR(75 MHz, CDCl ): d
A mixture of 11 (0.9 g, 0.971 mmol), triphenylphosphine
(1.008 g, 3.8 mmol), triiodoimidazole (0.69 g, 1.55 mmol)
and imidazole (0.133 g, 1.96 mmol) was treated as
described for compound 12 giving 0.456 g (52.6%) color-
less crystals of compound 13. Thermotropic properties:
3
(ppm) ˆ 164.2 (s, Cq), 155.0 (s, Ph-Cq), 151.4 (s, Ph-Cq),
138.1 (s, Ph-Cq), 137.2 (s, Ph-Ct), 135.1 (s, Ph-Cq), 131.9 (s,
Ph-Cq), 131.0, 129.6, 127.9, 121.5, 116.8 (5s, Ph-Ct), 101.6
(s, C-1), 101.4 (s, acetal-C), 80.4, 74.6, 73.3, 66.6 (4s, C-2,
C-3, C-4, C-5), 68.8 (s, C-6), 35.3 (s, Ph-CH2), 32.0, 31.8,
29.6, 29.4, 29.4, 22.8 (6s, CH2), 14.3 (s, CH3); 19F NMR
(235 MHz, CDCl3); d (ppm) ˆ À80.5 (s, CF3), À85.8 (m,
SCF2), À118.8 (m, CF2), À121.1 (s, CF2), À122.5 (s, CF2),
À125.8 (s, CF2).
mp 150 8C, SA-phase, cp 214 8C, ‰aŠ22: ‡17.98 (CHCl3,
D
c ˆ 1:00).
1H NMR(250 MHz, CDCl 3): d (ppm) ˆ 8.23 (m, 2H, Ph),
7.80 (m, 2H, Ph), 7.58 (m, 2H, Ph), 7.23 (m, 2H, Ph), 7.10
(m, 2H, Ph), 7.00 (m, 2H, Ph), 6.25 (d, 3J2=3 ˆ 10:1 Hz, 1H,
H-2 or H-3), 5.93 (m, 1H, H-1), 5.85 (dd, 1H, H-2 or H-3),
5.65 (s, 1H, acetal-H), 4.45±4.35 (m, 2H, H-4, H-6a), 3.91
(m, 2H, H-5, H-6b), 2.55 (t, 2H, a-CH2), 1.55±1.27 (m, 12H,
C40H39F13O8S (926.78): Calcd. C: 51.84%, H: 4.24%, S:
3.46%; found C: 51.63%, H: 4.19%, S: 3.61%.
3.9. (4-Perfluorohexylsulfanyl-phenyl)-(R)-4,6-O-[40-(4-
perfluorohexylsulfanyl)-benzoyloxy]-benzylidene-2,3-
dideoxy-b-D-erythro-hex-2-enopyranoside (12)
CH2), 0.88 (t, 3H, CH3); 13C NMR(63 MHz, CDCl ): d
3
(ppm) ˆ 163.9 (s, Cq), 154.8 (s, Ph-Cq), 151.2 (s, Ph-Cq),
137.3 (s, Ph-Cq), 137.1 (s, Ph-Ct), 135.3 (s, Ph-Cq), 131.8 (s,
Ph-Cq), 131.7, 127.6 (2s, C-2, C-3), 129.3 (s, Ph-Ct), 127.5
(s, Ph-Ct), 121.4, 116.7 (2s, Ph-Ct), 101.4 (s, acetal-C), 97.0
(s, C-1), 74.8, 70.9 (2s, C-4, C-5), 69.1 (s, C-6), 35.2, 31.9,
31.7, 29.5, 29.3, 22.7 (6s, CH2), 14.1 (s, CH3); 19F NMR
(235 MHz, CDCl3): d (ppm) ˆ À80.5 (s, CF3), À85.8 (m,
SCF2), À118.8 (m, CF2), À121.1 (s, CF2), À122.5 (s, CF2),
À125.8 (s, CF2).
A mixture of compound 9 (700 mg, 0.6 mmol), triphe-
nylphosphine (630 mg, 2.42 mmol), triiodoimidazole [19]
(431 mg, 0.97 mmol) and imidazole (83 mg, 1.23 mmol) in
dry xylene (25 ml) was stirred for 3 h at 130 8C under argon
atmosphere. After completion of the reaction (tlc-control,
eluent toluene RF ˆ 0:36), this mixture was cooled down to
room temperature, diluted with toluene (25 ml), and dec-
anted into a beaker containing saturated aq. NaHCO3-solu-
tion (150 ml). The residue was dissolved in a small volume
acetone and the solution was also added to the beaker. After
stirring for 10 min and ®ltration, the organic phase was
successively washed with 5% aq. Na2S2O3-solution, satu-
rated aq. NaHCO3-solution and water and then dried
(Na2SO4). Then the solution was concentrated under
reduced pressure and the crude product was puri®ed by
¯ash chromatography (eluent toluene RF ˆ 0:36). After
recrystallization from toluene, colorless crystals of 12
C40H37F13O6S (892.77): Calcd. C: 53.81%, H: 4.18%, S:
3.59%; found C: 53.58%, H: 4.21%, S: 3.64%.
3.11. (4-Octylphenyl)-(R)-4,6-O-[40-(4-
perfluorhexylsulfanyl)-benzoyloxy]-benzylidene-2,3-
dideoxy-b-D-erythro-hexopyranoside (14)
The ole®n 13 (300 mg, 0.336 mmol) was dissolved in
ethanol/EtOAc (1:1 (v/v), 10 ml). An amount of 20 mg of
palladium on charcoal (10%) was added. Under a hydrogen
atmosphere (1 atm) hydrogenation was carried out at room
temperature overnight. After ®ltration, the charcoal was
washed with ethanol and ethyl acetate. The combined
organic phases were concentrated under reduced pressure
and the residue was puri®ed by column chromatography
(384 mg, 56.5%) were obtained; mp 168 8C, SA-phase, cp
22
D
186 8C, ‰aŠ ‡7.48 (CHCl3, c ˆ 1:09).
1H NMR(300 MHz, CDCl 3): d (ppm) ˆ 8.23 (m, 2H, Ph),
7.80 (m, 2H, Ph), 7.58 (m, 4H, Ph), 7.24 (m, 2H, Ph), 7.12

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D. Schwabisch, R. Miethchen / Journal of Fluorine Chemistry 120 (2003) 85±91
91
(eluent toluene RF ˆ 0:33). Compound 14 was recrystal-
C26H17F13O5S (688.46): Calcd. C: 45.36%, H: 2.49%, S:
4.66%; found C: 45.64%, H: 2.15%, S: 4.79%.
lized from a small volume toluene yielding 0.284 g (95%) of
colorless crystals; mp 170 8C, SA-phase, cp 195 8C, ‰aŠ24:
D
À4.78 (CHCl3, c ˆ 1:12).
1H NMR(250 MHz, CDCl 3): d (ppm) ˆ 8.24 (m, 2H, Ph),
7.81 (m, 2H, Ph), 7.59 (m, 2H, Ph), 7.23 (m, 2H, Ph), 7.10
(m, 2H, Ph), 6.94 (m, 2H, Ph), 5.60 (s, 1H, acetal-H), 5.22
Acknowledgements
The authors are grateful to Prof. Dr. Manfred Michalik
(IfOK Rostock) for recording the NMR spectra, Prof. Dr.
3
3
(dd, J1=2a ˆ 2:1 Hz, J1=2b ˆ 9:8 Hz, 1H, H-1), 4.33 (dd,
3J3=4 ˆ 4:6 Hz, 3J4=5 ˆ 10:5 Hz, lH, H-4), 3.83 (dd, 1H, H-
6a), 3.02 (m, 2H, H-5, H-6b), 2.33 (t, 2H, a-CH2), 2.22, 1.90
(2 m, 2 Â 2H, H-2, H-3), 1.60±1.28 (m, 12H, CH2), 0.88 (t,
3H, CH3); 13C NMR(63 MHz, CDCl 3): d (ppm) ˆ 163.9 (s,
Cq), 154.8 (s, Ph-Cq), 151.1 (s, Ph-Cq), 137.1 (s, Ph-Ct),
135.6 (s, Ph-Cq), 131.8 (s, Ph-Cq), 130.8, 129.3 (2s, Ph-Ct),
127.6 (s, Ph-Ct), 121.4, 116.3 (2s, Ph-Ct), 101.1 (s, acetal-C),
99.7 (s, C-1), 77.3 (s, C-4), 70.7 (s, C-5), 69.3 (s, C-6), 35.2,
31.9, 31.7 (3s, CH2), 30.5 (s, C-2 or C-3), 29.5, 29.3 (2s,
È
Christoph Schick (Universitat Rostock, FB Physik) for DSC
measurements, and Angela Niemann for technical assis-
tance.
References
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(1995) 1696±1712.
CH2), 27.5 (s, C-2 or C-3), 22.7 (s, CH2), 14.1 (s, CH3); 19
F
NMR(235 MHz, CDCl 3): d (ppm) ˆ À80.5 (s, CF3), À85.8
(m, SCF2), À118.8 (m, CF2), À121.1 (s, CF2), À122.5 (s,
CF2), À125.8 (s, CF2).
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C40H39F13O6S (894.79): Calcd. C: 53.69%, H: 4.39%, S:
3.58%; found C: 53.31%, H: 4.30%, S: 3.62%.
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3.12. 3-Deoxy-(R)-4,6-O-[40-(4-perfluorohexylsulfanyl)-
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È
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(2000) 163±168.
The ole®n 12 (300 mg, 0.265 mmol) was hydrogenated as
described for compound 13 (eluent toluene RF ˆ 0:34)
yielding 0.136 g (75%) of colorless crystals after recrystal-
lization from a small volume toluene; mp 136 8C, SA-phase,
[8] R. Miethchen, M. Hein, Carbohydr. Res. 327 (2000) 169±183.
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55±60.
cp 160 8C; ‰aŠ26: ‡17.78 (CHC13, c ˆ 1:09).
D
1H NMR(300 MHz, CDCl 3): d (ppm) ˆ 8.22 (m, 2H, Ph),
7.79 (m, 2H, Ph), 7.58 (m, 2H, Ph), 7.22 (m, 2H, Ph), 6.33
(m, 1H, H-1), 5.64 (s, 1H, acetal-H), 4.73 (m, 1H, H-2), 4.40
(m, 1H, H-6a), 3.93 (m, 1H, H-4), 3.83±3.74 (m, 2H, H-5, H-
[15] H.L. Nguyen, J. Dedier, H.T. Nguyen, J.C. Rouillon, G. Sigaud, Liq.
Cryst. 26 (1999) 1637±1644.
6b), 2.30 (m, 2H, H-3); 13C NMR(75 MHz, CDCl ): d
3
[16] E. Smits, J.B.F.N. Engberts, R.M. Kellog, H.A. van Doren, J. Chem.
Soc., Perkin Trans. 1 (1996) 2858±2873.
 Â
[17] G. Zemplen, A. Gerecs, I. Hadacsy, Ber. Dtsch. Chem. Ges. 69
(ppm) ˆ 163.9 (s, Cq), 151.1 (s, Ph-Cq), 143.1 (s, C-1), 137.1
(s, Ph-Ct), 135.5 (s, Ph-Cq), 131.9 (s, Ph-Cq), 130.8, 127.6,
121.4 (3s, Ph-Ct), 101.0 (s, acetal-C), 98.7 (s, C-2), 75.1,
69.9 (2s, C-4, C-5), 68.9 (s, C-6), 26.3 (s, C-3); 19F NMR
(235 MHz, CDCl3): d (ppm) ˆ À80.5 (s, CF3); À85.8 (m,
SCF2), À118.8 (m, CF2), À121.1 (s, CF2), À122.5 (s, CF2),
(1936) 1827±1829.
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Cryst. Liq. Cryst. Sci. Technol. Sect. A 260 (1995) 185±200.
[19] P.J. Garegg, B. Samuelsson, Synthesis (1979) 813±814.
[20] J. Leonhard, B. Lygo, G. Procter, Praxis der Organischen Chemie,
VCH Verlag, Weinheim, 1996.
‡
À125.8 (s, CF2); MS-CI (isobutane) m=z ˆ 689 [M ‡ H] .